Lily goes to her appointment with the fertility expert, Dr. John Stangel (Neil Patrick Harris), who looks exactly like Barney, save for a beard and dark brown hair.
After some misunderstandings, Lily finally sees Barney and Stangel in the same room together and is satisfied that they are two different people.
He returns home to produce the sample, only to find that his parents have dropped by for a surprise visit.
Ted learns that Sandy is bald and wears a toupee; he snaps a picture, and tells Robin to show their office.
Lily pulls up in a taxi and tearfully informs Marshall that his father was rushed to the hospital after having a fatal heart attack.
The twist ending of Marshall's father's death was the result of show co-creators and producers Carter Bays and Craig Thomas' desire to explore the issue of the characters experiencing such a loss.
As the final scene of the episode closes, a parking meter is in the background displaying a red "expired" state.
[3] According to Bays, the countdown was used to give an early signal to the audience that something big was about to happen at the end of the episode.